Mediums will have a stack point just a hair past your draw length, the bow will feel smooth right to 28 but not much past it might make it to 29, it will vary by manufacturer, anyway this is not a bad thing, it will actually allow you to use the full efficiency and power potential of the limbs. If you prefer more of a pull-through feeling of smoothness you could go with longs or xtra longs, depending on your bow length preference. Mediums will give you a 56" bow, longs 58", xL's 60" and so forth.
ILF risers generally gain 1# per inch so say limbs are rated on a 17" riser, on a 13" they will be about 4 pounds heavier. This again will vary somewhat. A bow scale is a good tool to have when doing ILF.